Should I continue with a level further maths in year 2

I want to do a degree in architecture in a top university and right now my alevels are maths, further maths, chemistry and art. I am getting my maths a level grade this year ( I’m hoping either an a or a*) and I don’t know whether to continue with further maths next year, do an AS or drop it completely. Will further maths really be that beneficial for an architecture degree or should I stick with 3 a levels?

To my knowledge, the top universities are only asking for 3As in random A Levels for architecture . There's no indication of what subjects they prefer or require.
Have you checked the entry requirements of your chosen universities?

Don't get me wrong, Having further maths on your application is an achievement; it's a challenging A Level (I know because I'm doing it). However, if it comes at a cost of getting straight As and A*s, then you might want to drop it.

Don’t sone places not count further maths as a subject on its own? It’s generally a 4th subject rather than one of 3.

see this from LSE

https://www.lse.ac.uk/study-at-lse/Undergraduate/Prospective-Students/How-to-Apply/Admissions-Information

so some do, some don't, so you'd best check all your various top picks are happy with it as 3rd a level